<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="../../dist/vue.js"></script>
  </head>
  <body>
    <div id="app">{{name}}</div>
    <script>
      const app = new Vue({
        data() {
          return {
            name: {
              foo: "foo",
            },
          };
        },
        mounted() {
          this.name = { bar: "bar" }; 

          this.name.foo = "bar";

          this.$set(this.name, "bar", "bar");
        },
      });
      app.$mount("#app");
    </script>
  </body>
</html>
